Caught porc chop puffed again

[Hondatek]

I caught my porcupine puffer puffed up again this week. I just was walking into the kitchen and there he was. This is the 3rd time since i got him in June that I seen this. The first pic is from June when I first caught him puffed and second is this week.he has grown quite a bit.

 

[LyndaB]

Don't they puff up when stressed? I don't know much about them but love watching them at the store....

 

[Hondatek]

Definitly yes they do puff under stress but they don't only puff because of it. I have read that they do that to get sand off of their bodies and I watched the first time I caught him it was right after a water change and he did it right next to the powerheads . I could see the sand blowing off him .